If this crime was by the same attackers, they were more vicious. A man called to say his friend was hurt, lying on a park bench. When paramedics arrived, they found the victim barely alive, his head bashed in, defense wounds on his arms.

Not long after the second victim died, police had a third report. Just after 4 a.m., a homeless man crawled from the Church by the Sea garden where he was jumped, and flagged down a crew of firefighters.

Within three hours and four miles, police think a group of two to four young men, either teens or in their early 20s, had put two homeless men in the hospital and one in the morgue.

While there is no direct evidence proving that the three beatings are by the same group, authorities are investigating them as such because of the similar times, locations and method of attack. Police said the attackers will face murder charges.

"It's senseless. If you look at these kids, it was almost like it was fun and games for them," said Scott Russell, a Fort Lauderdale police officer who heads the department's crisis intervention team. "It looked like they were laughing and finding great joy in what they were doing, which made it more horrific."

Drifter Norris Gaynor, 45, did not survive severe blows to his head. Police did not release the identity of the two other men, whose conditions were unknown late Thursday.

"This is a heinous crime that will not go unpunished," said Fort Lauderdale police spokeswoman Katherine Collins.

Security cameras captured scenes of the first attack, in front of the Florida Atlantic University and Broward Community College higher education building on Las Olas Boulevard. The tape shows two young men chasing and beating a 58-year-old homeless man at the front door with bats. One of the teens stumbles as the man tries to defend himself. As the two teens run off, headlights from a dark-colored car or truck can be seen shining west on Las Olas Boulevard. Collins said she had no information about that vehicle, although authorities said Thursday they are looking for a white van with no markings.

Paramedics took the first victim to Broward General Medical Center in Fort Lauderdale for head trauma and defense fractures.

The beating spree next moved a few blocks southwest, to Riverwalk Linear Park, also called Esplanade Park, in the shadow of the Broward Center for the Performing Arts. In a secluded, western portion of the park near the water, the attackers beat Gaynor, who died at Broward General.

Collins said Gaynor may have been attacked as he slept on a park bench there. Detectives later tore the bench out of the ground to scour it for evidence. Bloodstains are all that remain.

The final attack came about 90 minutes later and three miles away. The attackers found a man sleeping on a bench in the Church by the Sea's memorial gardens and beat him severely, Collins said. The man crawled to Mayan Drive with a towel wrapped around his head, and he flagged down a passing fire crew who took him to the hospital.

"He claims that while sleeping he was attacked," said Assistant Chief Stephen McInerny with Fort Lauderdale Fire-Rescue.

Advocates say random violence against the homeless has always existed and is on the rise.

South Florida has had at least five cases of homeless-related killings by teens or young adults in the past two decades.

In 1986, in West Palm Beach, four teens decided, as a police report put it: to "roust some bums" for fun and beat a homelss man to death. In 1996, a 40-year-old homeless man was punched, kicked and stomped to death by a gang of teens in Pompano Beach.

"It's one of the shameful secrets we have, the beating of homeless for sport," said Marti Forman, CEO of the Cooperative Feeding Program in Fort Lauderdale. "It's a recreation thing, it's an initiation for gangs and fraternities. I see it in the kitchen in the mornings, people coming in with their black eyes and broken teeth."

Seldom, she said, is it caught on camera, as in this case.

"Thank God for that video," she said. "There has to be outrage in the community before someone says, `Well, how prevalent is this?'"

The National Coalition for the Homeless, which tracks random violence against the homeless using news and police reports, notes that in 2004, 25 homeless people were killed and 80 non-lethal attacks reported. That's a jump of 67 percent since 2002. Most of those accused were in their teens or early 20s.

"People think that homeless people are not human beings and that it's OK to hurt them and, most importantly, they think they can get away with it," said acting executive director Michael Stoops.

Stoops also points to the popularity of a series of videos and Internet clips known as "Bum Fights" that show homeless people being beaten up as a form of entertainment.

"When young people see that, they say, `I do can do that!'" Stoops said. "It's a copy-cat kind of thing."

On Thursday, Officers Jaime Costas and Russell, went to a homeless dinner offered by St. Andrews United Methodist Church and handed out fliers asking for help. As Costas described what happened to the three men that morning, one man gasped:

"Oh my God!"

Gaynor, the homeless man who died, had stayed at least briefly at the Broward Outreach Center in Pompano Beach. Several people there recognized Gaynor's photograph, but few knew him.

"He was pretty much to himself. He was kind of a wiry person, always on the move."

Gaynor has a short criminal history in Florida, according to Florida Department of Law Enforcement records, including charges of lewd and lascivious behavior in Miami-Dade County in 1990 and a one-year probation sentence in 1992 for aggravated battery there. On Dec. 29, he was arrested on a charge of indecent exposure by Hollywood police, according to Broward County court records. Further details were not available Thursday.

Sean Cononie, who runs a homeless shelter in downtown Hollywood, was worried. "If they don't catch these guys, it's probably going to happen again," he said. "The sad part is they reason they do it, `For kicks, for fun.' How does society address that?"

Ron Slaby, a developmental psychologist at the Center for Media and Child Heath at Children's Hospital Boston, said violence in the media, home and community are likely contributing factors.

He said the attackers are likely to have developed a superiority-inferiority complex that led them to believe the homeless are less than human. He said they are likely to have been exposed to media that reinforced this, as well as video games that "trained" them to kill without emotion. And, while in a group, Slaby said they likely experienced heightened excitement and diminished responsibility and inhibitions.

"There could be a certain level of gang mentality," he said, "a certain type of superiority ... where others who are `inferior' deserve to be done away with."

Anyone who has information is asked to call Crime Stoppers at 954-493-8477.

Staff Writer Alva James-Johnson and Staff Researchers William Lucey and Barbara Hijek contributed to this report.